cis/trans-Isomerisation of triolein, trilinolein and trilinolenin induced by heat treatment

Trans Fatty Acids and Human Health

“…Effect of cooking heat (185 ±5°C) on the fatty acids composition of sunflower oil, with the addition of the natural antioxidants of a rosemary extract (SOR) and of lutein (SOL) www.intechopen.com Trans Fatty Acids and Human Health 53 start to the end of the treatment (P <0.001), and also the decreases in trans C 18:1, t-9 production with the addition of rosemary oil and lutein were statistically significant in comparison with the control (SOR vs. sunflower oil: 0.32% vs. 0.45%; SOL vs. sunflower oil: 0.24% vs. 0.45%; P <0.001 for both). These data are consistent with an earlier report where there were reductions in trans-isomerisation and polar compounds in model oils when α-tocopherol (1%) was added as an antioxidant (Tsuzuki et al, 2008).…”

Study of the Formation of trans Fatty Acids in Model Oils (triacylglycerols) and Edible Oils during the Heating Process

“…Thus, our results support those of the previous studies. 2,5,8 One previous study reported a linear relation between the amounts of trans 18:1 in several vegetable oils and the heated periods. 2 This feature could be found in trans 18:1 in the heated oils investigated by this study.…”

“…Previous studies have reported that the continuous heating of vegetable oils produced a small amount of trans fatty acids. 2,5,8 We also investigated the effect of thermally induced oxidative stress on the cis-trans isomerization of double bounds in lipids, using highly purified triacylglycerols. Triolein (cis-9; 0.5 g) was heated at 160ºC, 180ºC, 200ºC, and 220ºC.…”

“…In that a small increase in the trans isomers of unsaturated triacylglycerols heated at around 180°C is correlated with thermal oxidation of the double bonds. 8 However, very little information is available about the relation between thermally induced lipid oxidation and the heat-induced isomerization of double bonds in the unsaturated fatty acids of edible oils and triacylglycerols.…”

The impact of technical cashew nut shell liquid on thermally-induced trans isomers in edible oils

“…9 t-OA, 9 t,12 t-LA, 9c,12 t-LA, and 9 t, 12c-LA are the trans isomers formed from processing OA and LA above 180°C Tsuzuki 2011). Trans isomerization of LNA can be achieved at high temperatures, producing 9 t,12c,15 t-LNA, 9 t,12 t,15c-LNA, 9c,12c,15c-LNA, 9c,12 t,15c-LNA, and 9 t,12c,15c-LNA as the predominant trans products (Tsuzuki et al 2008). Previous studies have also reported that the formation of these trans isomers at longer heating times and higher temperatures was also associated with a decrease in unsaturated fatty acid content (Li et al 2012).…”